onMount() — svelte Function Reference

Architecture documentation for the onMount() function in index-client.js from the svelte codebase.

Function javascript SharedInternal BitFlags calls 3 called by 1

Entity Profile

SharedInternal→ BitFlags→ onMount() — svelte Function Reference

Dependency Diagram

graph TD
  12342fb2_7ca7_b519_b701_5203cbd52362["onMount()"]
  717fc8d5_bdb4_4b73_d6c5_c4a367a60cf2["index-client.js"]
  12342fb2_7ca7_b519_b701_5203cbd52362 -->|defined in| 717fc8d5_bdb4_4b73_d6c5_c4a367a60cf2
  bf9532b7_3ab4_e735_2565_8aee52926f7b["onDestroy()"]
  bf9532b7_3ab4_e735_2565_8aee52926f7b -->|calls| 12342fb2_7ca7_b519_b701_5203cbd52362
  69870c62_aad9_b77a_8c01_8940b029a029["init_update_callbacks()"]
  12342fb2_7ca7_b519_b701_5203cbd52362 -->|calls| 69870c62_aad9_b77a_8c01_8940b029a029
  ea5280ff_3b87_42ee_3823_3570b76a5779["push()"]
  12342fb2_7ca7_b519_b701_5203cbd52362 -->|calls| ea5280ff_3b87_42ee_3823_3570b76a5779
  a814b193_e12a_4037_c3c8_dfd45f3bd0bb["untrack()"]
  12342fb2_7ca7_b519_b701_5203cbd52362 -->|calls| a814b193_e12a_4037_c3c8_dfd45f3bd0bb
  style 12342fb2_7ca7_b519_b701_5203cbd52362 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/svelte/src/index-client.js lines 91–104

export function onMount(fn) {
	if (component_context === null) {
		e.lifecycle_outside_component('onMount');
	}

	if (legacy_mode_flag && component_context.l !== null) {
		init_update_callbacks(component_context).m.push(fn);
	} else {
		user_effect(() => {
			const cleanup = untrack(fn);
			if (typeof cleanup === 'function') return /** @type {() => void} */ (cleanup);
		});
	}
}